Two lifting cables are needed for lifeboats; one is fastened to the hook in the bow of the boat and the other to the hook in the stern. As both hooks must be loosened from the loop simultaneously, the disengagement has to be performed by remote control. Either release wires or hydraulics are used. This is also the case with the present invention.
It is, furthermore, common for the hooks to be mounted in bearings between two supporting plates, so that the plates, if correctly designed, help in loosening the loop when the hook turns. This is also the case with a hook designed in accordance with the present invention.
Most disengaging devices function only when the hook is not loaded, others only when the hook is loaded, and all only when the safety lock is released. Usually they cannot be re-engaged after disengagement without fairly complicated measures. Many of the devices are complicated in structure, which makes them heavy and expensive.